1. Field of the Invention
The present invention relates to a vehicle control system for detecting an object ahead of a vehicle by an object detector mounted on the vehicle and controlling the vehicle based on the detection result.
2. Description of the Related Art
Japanese Patent Application Laid-open No. 5-174296 discloses an inter-vehicle distance detection and warning system in which the distance between an own vehicle and a preceding vehicle is detected by a radar device and a warning is issued to a driver when the inter-vehicle distance becomes a predetermined value or less, to thereby prevent collision. A detection area of the radar device is changed according to change in the speed of the own vehicle.
In the above-mentioned conventional arrangement, the detection area of the radar device is changed according to the vehicle speed but, even when the vehicle speed is the same, the possibility of collision differs between a case where the driver has noticed the inter-vehicle distance decreasing to have an intention of decelerating and the other cases. Therefore, it is not appropriate to change the detection area according to the vehicle speed alone without taking into consideration the driver's intention.
Further, the detection area is generally set to be along the travel locus of the subject vehicle and substantially as wide as a lane so that the radar device detects a preceding vehicle. However, when there is an intersection, etc. in front of the own vehicle, the driver must also pay attention to any vehicles cutting in from the side into the travel locus of the own vehicle. Therefore, in detection of a preceding vehicle based on a narrow detection area substantially having the lane width, there might be a gap between the detection and the driver's consciousness. Immoderate widening of the detection area is undesirable in solving this problem, because a vehicle in the opposite lane might be erroneously detected, or the data processing load of the object detection system might increase.